title: Recurrent glioblastoma: volumetric assessment and stratification of patient survival with early posttreatment magnetic resonance imaging in patients treated with bevacizumab.
abstract: BACKGROUND
  Despite a high radiographic response rate in patients with recurrent glioblastoma following bevacizumab therapy, survival benefit has been relatively modest. We assess whether tumor volume measurements based on baseline and early posttreatment MRI can stratify patients in terms of progression-free survival (PFS) and overall survival (OS).
  
  
  METHODS
  Baseline (-4 +/- 4 days) and posttreatment (30 +/- 6 days) MRI exams of 91 patients with recurrent glioblastoma treated with bevacizumab were retrospectively evaluated for volume of enhancing tumor as well as volume of the T2/FLAIR hyperintensity. Overall survival (OS) and progression-free survival (PFS) were assessed using volume parameters in a Cox regression model adjusted for significant clinical parameters.
  
  
  RESULTS
  In univariable analysis, residual tumor volume, percentage change in tumor volume, steroid change from baseline to posttreatment scan, and number of recurrences were associated with both OS and PFS. With dichotomization by sample median of 52% change of enhancing volume can stratify OS (52 weeks vs. 31 weeks, P = .013) and PFS (21 weeks vs. 12 weeks, P = .009). Residual enhancing volume, dichotomized by sample median of 7.8 cm(3) , can also stratify for OS (64 weeks vs. 28 weeks, P < .001) and PFS (21 weeks vs. 12 weeks, P = .036).
  
  
  CONCLUSIONS
  Volumetric percentage change and absolute early posttreatment volume of enhancing tumor can stratify survival for patients with recurrent glioblastoma receiving bevacizumab therapy.
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Raymond Y
authors.initials: RY
authors.lastname: Huang
authors.forename: Rifaquat
authors.initials: R
authors.lastname: Rahman
authors.forename: Alhafidz
authors.initials: A
authors.lastname: Hamdan
authors.forename: Caroline
authors.initials: C
authors.lastname: Kane
authors.forename: Christina
authors.initials: C
authors.lastname: Chen
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Norden
authors.forename: David A
authors.initials: DA
authors.lastname: Reardon
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Mukundun
authors.forename: Patrick Y
authors.initials: PY
authors.lastname: Wen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000068258:Bevacizumab; D001932:Brain Neoplasms / Q000175:diagnosis / Q000188:drug therapy* / Q000473:pathology*; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D005909:Glioblastoma / Q000175:diagnosis / Q000188:drug therapy* / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000188:drug therapy* / Q000473:pathology*; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab
keywords: bevacizumab; glioblastoma; magnetic resonance imaging; survival; volumetric analysis